The place is Trinity Site, where the first nuclear weapon was fired. The photo shows Oppenheimer & Groves (two of the most important people in the country) wearing regular clothing at ground zero shortly after the war. On open-house days you can walk right in & stand in that very same place. An hour's exposure here is about equal to 10 hours of normal background exposure.

I had a thought along the lines of yours -- it does not look like a 40's photo. I found it identified as a photo of Fuchs, but I won't be surprised if someone identifies it as a photo of an actor in a documentary. National Geographic should be provide photo credits that would make such details obvious. Nice picture, though -- it has the nerdy spy thing goin' on.